18 research outputs found

    Projected changes in heat load in Carpathian Basin cities during the 21st century

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    In this study the changes in the nighttime heat load in Carpathian Basin cities during the 21st century were examined. To quantify the heat load, the tropical night climate index was used. The MUKLIMO_3 local scale climate model was used to describe the urban processes and the land use classes were defined by the local climate zones. The expected change was examined over three periods: the 1981–2010 was taken as reference period using the Carpatclim database and the 2021–2050 and 2071–2100 future periods using EURO-CORDEX regional model simulation data for two scenarios (RCP4.5 and RCP8.5). To combine the detailed spatial resolution and the long time series, a downscaling method was applied. Our results show that spectacular changes could be in the number of tropical nights during the 21st century and the increasing effect of the urban landform is obvious. In the near future, a slight increase can be expected in the number of tropical nights, which magnitude varies from city to city and there is no major difference between the scenarios. However, at the end of the century the results of the two scenarios differ: the values can be 15-25 nights in case of RCP4.5 and 30-50 nights in case of RCP8.5. The results show that dwellers could be exposed to high heat load in the future, as the combined effect of climate change and urban climate, thus developing various mitigation and adaptation strategies is crucial

    Model development for the estimation of urban air temperature based on surface temperature and NDVI - a case study in Szeged

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    Predictive models for urban air temperature (Tair) were developed by using urban land surface temperature (LST) retrieved from Landsat-8 and MODIS data, NDVI retrieved from Landsat-8 data and Tair measured by 24 climatological stations in Szeged. The investigation focused on summer period (June−September) during 2016−2019 in Szeged. The relationship between Tair and LST was analyzed by calculating Pearson correlation coefficient, root-mean-square error and mean-absolute error using the data of 2017−2019, then unary (LST) and binary (LST and NDVI) linear regression models were developed for estimating Tair. The data in 2016 were used to validate the accuracy of the models. Correlation analysis indicated that there were strong correlations during the nighttime and relatively weaker ones during the daytime. The errors between Tair and LSTMODIS-Night was the smallest, followed by LSTMODIS-Day and LSTLandsat-8 respectively. The validation results showed that all models could perform well, especially during nighttime with an error of less than 1.5℃. However, the addition of NDVI into the linear regression models did not significantly improve the accuracy of the models, and even had a negative effect. Finally, the influencing factors and temporal and spatial variability of the correlation between Tair and LST were analyzed. LSTLandsat-8 had a larger original error with Tair, but the regression model based on Landsat-8 had a stronger ability to reduce errors

    Impact of copper and iron binding properties on the anticancer activity of 8-hydroxyquinoline derived Mannich bases.

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    The anticancer activity of 8-hydroxyquinolines relies on complex formation with redox active copper and iron ions. Here we employ UV-visible spectrophotometry and EPR spectroscopy to compare proton dissociation and complex formation processes of the reference compound 8-hydroxyquinoline (Q-1) and three related Mannich bases to reveal possible correlations with biological activity. The studied derivatives harbor a CH2-N moiety at position 7 linked to morpholine (Q-2), piperidine (Q-3), and chlorine and fluorobenzylamino (Q-4) substituents. Solid phase structures of Q-3, Q-4·HCl·H2O, [(Cu(HQ-2)2)2]·(CH3OH)2·Cl4·(H2O)2, [Cu(Q-3)2]·Cl2 and [Cu(HQ-4)2(CH3OH)]·ZnCl4·CH3OH were characterized by single-crystal X-ray diffraction analysis. In addition, the redox properties of the copper and iron complexes were studied by cyclic voltammetry, and the direct reaction with physiologically relevant reductants (glutathione and ascorbic acid) was monitored. In vitro cytotoxicity studies conducted with the human uterine sarcoma MES-SA/Dx5 cell line reveal the significant cytotoxicity of Q-2, Q-3, and Q-4 in the sub- to low micromolar range (IC50 values 0.2-3.3 μM). Correlation analysis of the anticancer activity and the metal binding properties of the compound series indicates that, at physiological pH, weaker copper(ii) and iron(iii) binding results in elevated toxicity (e.g.Q4: pCu = 13.0, pFe = 6.8, IC50 = 0.2 μM vs.Q1: pCu = 15.1, pFe = 13.0 IC50 = 2.5 μM). Although the studied 8-hydroxyquinolines preferentially bind copper(ii) over iron(iii), the cyclic voltammetry data revealed that the more cytotoxic ligands preferentially stabilize the lower oxidation state of the metal ions. A linear relationship between the pKa (OH) and IC50 values of the studied 8-hydroxyquinolines was found. In summary, we identify Q-4 as a potent and selective anticancer candidate with significant toxicity in drug resistant cells

    Solution equilibrium, structural and cytotoxicity studies on Ru(η6-p-cymene) and copper complexes of pyrazolyl thiosemicarbazones

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    Solution chemical properties of two bidentate pyrazolyl thiosemicarbazones 2-((3-methyl-1-phenyl-1H-pyrazol-4-yl)methylene)hydrazinecarbothioamide (Me-pyrTSC), 2-((1, 3-diphenyl-1H-pyrazol-4-yl)methylene)hydrazinecarbothioamide (Ph-pyrTSC), stability of their Cu(II) and Ru(η6-p-cymene) complexes were characterized in aqueous solution (with 30% DMSO) by the combined use of UV–visible spectrophotometry, 1H NMR spectroscopy and electrospray ionization mass spectrometry in addition to their solid phase isolation. The solid phase structures of Me-pyrTSC∙H2O, [Ru(η6-p-cymene)(Me-pyrTSC)Cl]Cl and [Cu(Ph-pyrTSCH−1)2] were determined by single crystal X-ray diffraction. High stability mononuclear Ru(η6-p-cymene) complexes with (N, S) coordination mode are formed in the acidic pH range, and increasing the pH the predominating dinuclear [(Ru(η6-p-cymene))2(L)2]2+ complex with μ2-bridging sulphur donor atoms is formed (where L− is the deprotonated thiosemicarbazone). [CuL]+ and [CuL2] complexes show much higher stability compared to that of complexes of the reference compound benzaldehyde thiosemicarbazone. [CuL2] complexes predominate at neutral pH. Me-pyrTSC and Ph-pyrTSC exhibited moderate cytotoxicity against human colonic adenocarcinoma cell lines (IC50 = 33–76 μM), while their complexation with Ru(η6-p-cymene) (IC50 = 11–24 μM) and especially Cu(II) (IC50 = 3–6 μM) resulted in higher cytotoxicity. Cu(II) complexes of the tested thiosemicarbazones were also cytotoxic in three breast cancer and in a hepatocellular carcinoma cell line. No reactive oxygen species production was detected and the relatively high catalase activity of SUM159 breast cancer cells was decreased upon addition of the ligands and the complexes. In the latter cell line the tested compounds interfered with the glutathione synthesis as they decreased the concentration of this cellular reductant

    Exclusive neuronal expression of SUCLA2 in the human brain

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    SUCLA2 encodes the ATP-forming subunit (A-SUCL-) of succinyl-CoA ligase, an enzyme of the citric acid cycle. Mutations in SUCLA2 lead to a mitochondrial disorder manifesting as encephalomyopathy with dystonia, deafness and lesions in the basal ganglia. Despite the distinct brain pathology associated with SUCLA2 mutations, the precise localization of SUCLA2 protein has never been investigated. Here we show that immunoreactivity of A-SUCL- in surgical human cortical tissue samples was present exclusively in neurons, identified by their morphology and visualized by double labeling with a fluorescent Nissl dye. A-SUCL- immunoreactivity co-localized >99% with that of the d subunit of the mitochondrial F0-F1 ATP synthase. Specificity of the anti-A-SUCL- antiserum was verified by the absence of labeling in fibroblasts from a patient with a complete deletion of SUCLA2. A-SUCL- immunoreactivity was absent in glial cells, identified by antibodies directed against the glial markers GFAP and S100. Furthermore, in situ hybridization histochemistry demonstrated that SUCLA2 mRNA was present in Nissl-labeled neurons but not glial cells labeled with S100. Immunoreactivity of the GTP-forming subunit (G-SUCL-) encoded by SUCLG2, or in situ hybridization histochemistry for SUCLG2 mRNA could not be demonstrated in either neurons or astrocytes. Western blotting of post mortem brain samples revealed minor G-SUCL- immunoreactivity that was however, not upregulated in samples obtained from diabetic versus non-diabetic patients, as has been described for murine brain. Our work establishes that SUCLA2 is expressed exclusively in neurons in the human cerebral cortex

    Postoperative differences between colonization and infection after pediatric cardiac surgery-a propensity matched analysis

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    BACKGROUND: The objective of this study was to identify the postoperative risk factors associated with the conversion of colonization to postoperative infection in pediatric patients undergoing cardiac surgery. METHODS: Following approval from the Institutional Review Board, patient demographics, co-morbidities, surgery details, transfusion requirements, inotropic infusions, laboratory parameters and positive microbial results were recorded during the hospital stay, and the patients were divided into two groups: patients with clinical signs of infection and patients with only positive cultures but without infection during the postoperative period. Using propensity scores, 141 patients with infection were matched to 141 patients with positive microbial cultures but without signs of infection. Our database consisted of 1665 consecutive pediatric patients who underwent cardiac surgery between January 2004 and December 2008 at a single center. The association between the patient group with infection and the group with colonization was analyzed after propensity score matching of the perioperative variables. RESULTS: 179 patients (9.3%) had infection, and 253 patients (15.2%) had colonization. The occurrence of Gram-positive species was significantly greater in the colonization group (p=0.004). The C-reactive protein levels on the first and second postoperative days were significantly greater in the infection group (p=0.02 and p=0.05, respectively). The sum of all the positive cultures obtained during the postoperative period was greater in the infection group compared to the colonization group (p=0.02). The length of the intensive care unit stay (p<0.001) was significantly longer in the infection group compared to the control group. CONCLUSIONS: Based on our results, we uncovered independent relationships between the conversion of colonization to infection regarding positive S. aureus and bloodstream results, as well as significant differences between the two groups regarding postoperative C-reactive protein levels and white blood cell counts

    Complement lectin pathway activation is associated with COVID-19 disease severity, independent of MBL2 genotype subgroups

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    IntroductionWhile complement is a contributor to disease severity in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, all three complement pathways might be activated by the virus. Lectin pathway activation occurs through different pattern recognition molecules, including mannan binding lectin (MBL), a protein shown to interact with SARS-CoV-2 proteins. However, the exact role of lectin pathway activation and its key pattern recognition molecule MBL in COVID-19 is still not fully understood.MethodsWe therefore investigated activation of the lectin pathway in two independent cohorts of SARS-CoV-2 infected patients, while also analysing MBL protein levels and potential effects of the six major single nucleotide polymorphisms (SNPs) found in the MBL2 gene on COVID-19 severity and outcome.ResultsWe show that the lectin pathway is activated in acute COVID-19, indicated by the correlation between complement activation product levels of the MASP-1/C1-INH complex (p=0.0011) and C4d (p&lt;0.0001) and COVID-19 severity. Despite this, genetic variations in MBL2 are not associated with susceptibility to SARS-CoV-2 infection or disease outcomes such as mortality and the development of Long COVID.ConclusionIn conclusion, activation of the MBL-LP only plays a minor role in COVID-19 pathogenesis, since no clinically meaningful, consistent associations with disease outcomes were noted
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